Flame resistant packaging system and method of making same

ABSTRACT

A flame resistant packaging system has an outer box and a flame and heat resistant liner inside the box. The liner is constructed of a layer of a ceramic fiber and a layer of metal foil. The edges of the liner are joined at a seam, forming a compartment for holding an article to be packaged. The foil layer of the liner faces the inside of the compartment. A patch, similarly constructed of foil and ceramic fiber, is attached over the seam to prevent hot gasses from entering the compartment at the seam. The compartment is substantially closed by folding the sides of the liner inward. End inserts, similarly constructed of foil and ceramic fiber, are inserted into the compartment to substantially cover the areas where the liner is folded to close the compartment.

CLAIM FOR PRIORITY

This application claims the priority of U.S. Provisional Application Ser. No. 61/411,194, filed Nov. 8, 2010, entitled “Flame And Heat Resistant Packaging System And Method Of Making Same,” which application is incorporated by reference into the present application.

BACKGROUND

1. Technical Field

This disclosure relates to packaging resistant to flame penetration, particularly packaging for shipping containers of oxidizing material.

2. Background

An example of packaging requiring resistance to flame penetration are the chemical oxygen generators used in the aviation industry, and commonly shipped in the cargo hold of an aircraft. The reader should note, however, that this disclosure is not limited to the protection of chemical oxygen generators, but is applicable to the enclosure of other types of gas containers, gas generators, explosives, or any container having chemical contents that may react under flames.

Various safety precautions are taken to prevent actuation of oxygen generators and similar devices during shipment. These precautions include enclosure of the chemical oxygen generator in a primary package that reduces the possibility of mechanical actuation. However, a fire in the cargo hold of an aircraft could raise the temperature of such a chemical oxygen generator enough to cause actuation of the generator, or cause actuation by flame penetration of the packaging to the generator. The present subject matter provides outer packaging, and a method making it, to mitigate the effect of such a fire on chemical oxygen generators contained in the packaging.

The National Transportation Safety Board (NTSB) determined that one of the probable causes of the May 11, 1996 crash of ValuJet Airlines flight No. 592 was a fire in the airplane's cargo compartment initiated and enhanced by the actuation of one or more chemical oxygen generators carried as cargo in violation of requirements in the Hazardous Materials Regulations (HMR 49 CFR Parts 171 through 180). Recommendations issued by the NTSB following this tragedy addressed both the initiation of the fire by the improperly packaged generators and the possible enhancement of an aircraft cargo-compartment fire by the oxygen produced by the generators or other cargo. A number of corrective measures were included in NTSB Docket HM-224A. The final rule pointed out the possibility of further reducing the risks by enclosure of boxes containing chemical oxygen generators in an overpack or outer packaging meeting certain flame penetration resistance, thermal protection and integrity standards.

Later rule-making procedures addressed the additional features of flame penetration resistance, thermal protection and integrity. In 2007, the Department of Transportation, Pipeline and Hazardous Materials Safety Administration, issued final rule HM224B, “Transportation of Compressed Oxygen, Other Oxidizing Gases and Chemical Oxygen Generators on Aircraft.” This regulation specifies that after Sep. 30, 2009, a chemical oxygen generator and a chemical oxygen generator installed in equipment, must be placed in a rigid outer packaging that, among other things, conforms to the requirements of The Flame Penetration Resistance Test in part III of Appendix F to 14 CFR part 25, applied to at least three specimens of the outer packaging of a specified dimension, and on all design features, within five minutes of application of the flame source; and the maximum allowable temperature at a point four inches above the test specimen, centered over the burner cone, must not exceed 205° C. (400° F.). Furthermore, a chemical oxygen generator in the rigid outer packaging, when placed in a 205° C. (400° F.) oven for three hours must not actuate.

Present packaging aimed at satisfying these requirements is bulky, complicated to assemble, and unduly expensive, or all three.

DRAWINGS

FIGS. 1 through 14 illustrate the making and assembly of embodiments of the packaging system.

FIG. 1 shows an exemplary cardboard outer box, laid flat.

FIG. 2 shows a perspective cut-away view of the exemplary cardboard box, as the same would appear folded to create the outer box structure.

FIG. 3 shows a foil flat for the liner of the cardboard box.

FIG. 4 shows a flat of ceramic fibers that cooperates with the folded foil flat of FIG. 3.

FIG. 5 shows a typical pattern for hot melt glue suitable for attaching the flat of ceramic fiber of FIG. 4 to the foil flat of FIG. 3.

FIG. 6 shows a perspective cut-away view of the exemplary foil and ceramic fiber insert that is located inside the cardboard box of FIG. 2.

FIG. 7 is a perspective view of a foil patch for covering seams and staples within the assembled embodiment.

FIG. 8 is a ceramic fiber insert for the patch of FIG. 7

FIG. 9 shows the assembly of the foil patch and the ceramic fiber insert of FIGS. 7 and 8.

FIG. 10 shows a typical pattern of neoprene glue used for assembly of the foil patch and the ceramic fiber insert of FIGS. 7 and 8.

FIG. 11 is an exploded view of the components of an embodiment of the packaging system.

FIG. 12 is a perspective view of an end insert for the packaging system container, constructed of foil and ceramic fiber.

FIG. 13 shows an exploded view of the construction of the end insert of FIG. 12.

FIG. 14 is a perspective cut-away view of an exemplary packaging system, assembled.

FIG. 14A shows cross-section details of the layers of the exemplary packaging system.

FIGS. 15 through 28 illustrate exemplary steps of assembly of components of the packaging system into a container for shipping heat and flame sensitive articles.

The drawings are not to scale.

DESCRIPTION

An “overpack,” is the container for a sensitive chemical cargo that is usually enclosed in some sort of primary packaging. The disclosed overpack comprises a box (110), preferably double-walled cardboard, which is lined with layers of metal foil and ceramic fiber paper that form an inner liner (160). The size and shape of the box (110) is determined by the number and size of containers to be placed in it. In one embodiment, the contents may be one or a number of individually packaged devices, such as chemical oxygen generators. (The reader should understand that the term “oxygen generator” in this application refers generally to any heat or flame-sensitive component of product.)

Flame penetration resistance can be provided by ceramic papers, felts or fabrics such as those offered by Unifrax, of Niagara Falls, N.Y., under the trade name of FIBERFRAX. For this purpose, such sheets of ceramic fiber (interchangeably called “felt,” “paper” or “fabric” in this application), preferably 1/16 inch to ¼ inch thick, preferably about ⅛ inch thick, are attached to one side of a cardboard carton. Such cartons are preferably double wall, 275 lb test, for shipping integrity. Packaging material other than cardboard could be used. The overall size and shape of the cardboard carton will be determined by the size of the container or equipment it will receive, allowing space for the ceramic fiber sheets, metal foil, and assembly means.

Metal foil (130), preferably aluminum foil, having a thickness of about 1 mil to 4 mils, preferably about 2 mils, provides a serviceable surface and protects the included ceramic paper (140). The foil (130) also prevents penetration of the compartment (225) by hot gasses from flames. Parts of the foil (130) will also be the points of attachment of the foil (130) and the ceramic paper (140) to the box (110). All surfaces of the ceramic paper (140) that will, at one time or another, be visible looking into the compartment (225) are covered with foil (130), and, where needed, additional foil (130) is provided for bonding. Any of a number of adhesive means are adequate; hot melt adhesive has been found suitable. An example of a suitable hot melt glue is Technomelt from Henkel Adhesives, of Elgin, Illinois. The surface of the foil (130) that will contact the included contents provides additional advantages of low coefficient of friction, allowing the intended contents to be slid into the box, and low emissivity, which slows heat transfer from a flame to the contents.

The figures illustrate the construction of the box with the liner (160) of foil (130) and ceramic fiber (140), per the following table of reference numerals:

Reference numeral Item 100 assembled packaging system 110 cardboard box form 120 fold lines 130 foil for liner 140 ceramic fiber flat for liner 150 ceramic fiber hot melt glue pattern for liner 160 folded foil and ceramic fiber insert in box pattern 165 edges of ceramic fiber/foil liner to be joined 170 foil for patch 180 ceramic fiber for patch 190 foil plus ceramic fiber patch folded for application 195 seam made at edges of liner 200 neoprene glue pattern for patch 210 staples 220 assembled end insert 225 compartment formed by fiber/foil 230 inner foil for end insert 240 ceramic fiber for end insert 250 outer foil for end insert 260 labels for outer foil of end insert 270 assembled packaging system 280 short end flaps of box 290 long end flaps of box 300 tape for sealing box

FIG. 1 shows an exemplary cardboard outer box (110), laid flat, having scoring for folding. FIG. 2 shows a perspective cut-away view of the exemplary cardboard box (110), as the same would appear folded to create the box (110) structure for transport of an article. FIG. 3 shows a foil flat (130) for the liner (160) of the cardboard box (110). FIG. 4 shows a flat (140) of ceramic fiber that cooperates with the foil flat (130) of FIG. 3 to create the ceramic fiber-foil inner liner (160) of the packaging system (100). FIG. 5 shows a pattern (150) for hot melt glue suitable for attaching the flat of ceramic fibers (140) of FIG. 4 to the foil flat (130) of FIG. 3.

After a laid-flat box (110) has been thus equipped with a ceramic paper and aluminum foil liner (160) as shown in the figures, the edges (165) of the liner (160) are lapped and stapled to make a joint or seam (195).

FIG. 6 is a perspective cut-away view of the assembled packaging system (100) before the patch (190) is applied over the seam (195) where the edges (165) of the inner liner (160) are abutted. FIG. 6 shows the liner (160) of foil (130) and ceramic fiber (140), inside the cardboard box (110), revealing the seam (195) and staples (210) to be covered by the patch (190), as discussed next.

The stapled seam (195) is covered with a patch (190) of ceramic paper (180) and metal foil (170), the various parts being bonded over the seam (195) using any of a variety of adhesives. We have found that neoprene glue is adequate. The foil side of the patch (190) should face the compartment (225).

FIG. 7 is a perspective view of a foil layer (170) for a patch (190) for covering the seam (195) and staples (210) within the assembled embodiment of the packaging system (100). FIG. 8 shows a ceramic fiber insert layer (180) that cooperates with the foil layer (170) shown in FIG. 7 to form the patch (190). FIG. 9 shows the assembly of the foil layer (170) and the ceramic fiber layer (180) for the patch (190), folded as it would be applied inside the liner (160) over the seam (195). FIG. 10 shows a typical pattern (200) of a neoprene glue application used for assembly of the foil layer (170) and the ceramic fiber layer (180) into the patch (190).

FIG. 11, not to scale, is an exploded view of the components of the packaging system (100) just discussed, as they would appear before the edges (165) of the combined foil (130) and ceramic fiber (140) layers are joined.

FIGS. 12 and 13 show the exemplary construction of an end insert (220) for covering the ends of the compartment (225) when the inner liner (160) is folded. The end insert (220) has a foil layer (230) over a layer (250) of ceramic fiber. An exploded assembly view of the end insert (220) is shown in FIG. 13. FIG. 13 shows a second, optional, foil layer (250) over the ceramic fiber layer (240), and also optional labels (260) to instruct the person assembling the system (100) that the continuous foil layer (230) should face toward the interior of the compartment (225).

FIG. 14 is a cut-away perspective view of the assembled packaging system, with the outer box (110), inner liner (160), patch (190) and end insert (220) in place. The end inserts (220) are used to assure substantially complete and continuous coverage of the ends of the compartment (225) where the liner (160) is folded, to block penetration of the compartment (225) of the box by hot gasses. Before the end inserts (220) are placed and the ends of the box (110) are closed, the open box (110) with the liner (160) inside can be collapsed, and multiple collapsed systems (100) can be stacked for storage and shipment.

Note that the box (110) may be any convenient size and shape, not necessarily the rectangular cross-section box (110) shown. In some embodiments, the staples (210) enter the wall of the box (110) and pass through the liner (160), thus attaching the liner (160) to the box (110).

A drawing of a schematic cross section of the wall of the flame resistant packaging system (100) is shown in FIG. 14A.

When the flame penetration-resistant system (100) is needed for shipment, it can be prepared for receiving and article to be transported according to the following steps, as generally illustrated in FIGS. 15-28.

The assembled and flattened packaging system (100) is retrieved from a storage location and placed on a workspace.

In FIG. 15, the system (100) is unfolded into a rectangular, open shape.

In FIG. 16, the liner (160) is scored with the fingers along all horizontal fold lines in the liner (160), to assist with proper folding of the foil and ceramic felt inner lining (160) to correspond to the horizontal fold lines of the cardboard box (110).

In FIGS. 17 and 18, the inner lining (160) is folded into the box (110) so that it is perpendicular to the outer body of the box (110), thus substantially closing the open end of the compartment (225). Merely for illustration, the box (110) in these examples is shown with a rectangular cross section, having a short side (280) and a long side (290).

In FIG. 19, the short sides (280) of the box (110) are folded, and then the long sides (290) are folded, completing closing of the box (110) on the end shown upright.

In FIG. 20, the folded bottom of the box (110) is secured using an “H” pattern of tape (300). A three-inch industrial grade tape with fiberglass yarn is preferred.

In FIG. 21, the previously secured bottom of the box (110) is placed on the workspace and the bottom end insert (220) is placed into the compartment (225) over the folded end of the liner (160), with the foil side of the insert (220) facing the compartment (225). Preferably, the insert (220) has labels (260) indicating the proper direction of placement.

FIG. 22 shows the inside of the system (100) with the correctly installed bottom insert (220).

In FIG. 23, the liner (160) is scored with the fingers along all horizontal fold lines in the liner (160) to assist with proper folding of the foil and ceramic felt liner (160) to correspond to the horizontal fold lines of the cardboard box (110).

In FIG. 24, the article to be shipped and any dunnage (not shown) are placed into the compartment (225) and the second end insert (220) is placed on top of the dunnage and article. The insert (220) should be substantially flush on the contents of the compartment (225).

In FIG. 25, a flap of the liner (160) is folded into the box (110) so that it is perpendicular to the outer body of the box (110).

In FIG. 26, the other flap of the liner (160) is folded into the box (110) so that it is perpendicular to the outer body of the box (110).

In FIG. 27, the short sides (280) of the box (110) are folded; then the long sides (290) are folded, completing closing of the box (110) on the end shown upright.

In FIG. 28, the folded bottom of the box (110) is secured using an “H” pattern of tape (300). A three-inch industrial grade tape with fiberglass yarn is preferred. This completes a sealed packaging system (270) with contents. 

1. A flame resistant packaging system, comprising: a box; a liner inside the box; the liner further comprising: a layer of ceramic fiber; a layer of foil; the liner having first and second edges; the first and second edges abutted at a seam, so that the liner forms an compartment; where the foil layer of the liner faces the compartment; the liner having folds substantially closing the compartment; a patch; the patch further comprising: a layer of ceramic fiber; a layer of foil; the patch disposed on the liner to cover the seam, so that the patch layer of foil faces the compartment; an end insert; the end insert comprising; a layer of ceramic fiber; a layer of foil; the end insert disposed inside the compartment so as to substantially cover the folds in the liner substantially closing the compartment, and; so that the layer of foil of the end-insert faces the compartment.
 2. The system of claim 1, where the foil is aluminum foil.
 3. The system of claim 1 where the foil is attached to the ceramic fiber with glue.
 4. The system of claim 1 where the first and second edges of the liner are joined by staples.
 5. The system of claim 4, where the box has a wall; and, the staples pass through the wall of the box and the liner.
 6. The system of claim 1, where the patch is attached to the liner with glue.
 7. The system of claim 1, where the end insert further comprises a second layer of foil attached to the ceramic fiber layer of the end insert.
 8. A method of making a flame resistant packaging system, comprising: constructing a liner comprising a layer of foil and a layer of ceramic fiber; the liner having first and second edges; joining the first and second edges of the liner at a seam, so as to form a compartment for receiving an article; attaching the liner to the inside of a box; and, covering the seam with a patch comprising a layer of foil and a layer of ceramic fabric.
 9. The method of claim 8, further comprising attaching the layer of foil and the layer of ceramic fiber with glue.
 10. The method of claim 8, where the attaching of the liner to the inside of the box further comprises connecting the liner and the box with staples.
 11. The method of claim 8, where the patch is attached to the liner over the seam with glue.
 12. The method of claim 8, where the compartment has an open end; the method further comprising: folding the liner so as to substantially close the compartment at the open end; placing an end insert inside the compartment over the location where the liner is folded to substantially close the compartment.
 13. The method of claim 12, where the end insert is constructed by: placing a layer of foil over a layer of ceramic fiber; and, folding the foil over the layer of ceramic fiber.
 14. A method of assembling a flame resistant packaging system for transport of an article, where the packaging system comprises a box having first and second openings, a flame and heat resistant liner having sides; the liner attached to the inside of the box to form a compartment; the method comprising: folding the sides of the liner to substantially close the compartment at the first opening; closing the first opening of the box corresponding to the first opening of the compartment over the liner; sealing the closed first opening of the box; placing a first end insert in the compartment over the location where the liner is folded to substantially close the compartment at the first opening; placing an article into the compartment; placing a second end insert in the compartment over the article; folding the sides of the liner to substantially close the compartment at the second opening; closing the second opening of the box corresponding the second opening of the compartment over the liner; and, sealing the closed second opening of the box. 